cover



1. COVER GRINDING MILL' SHEET 2.

- APPLICATI'ON FILED NOV. I6. 1915. Lwmw,

Patented Aug.

5 SHEETS 1. W. COVER.

GRINDING MILL.

APPLICATION FILED Nov. I6. I9I5.

Patemed Aug. 15,1916..

5 SHEETS-SHEET 3.

LJWJCQVER. GRINDING MILL. APPLICATION FILED NOV. 16, i915.

5 SHEETS-SHEET 4.

Pat-@med Aug. 15, 1916.-

J. W. COVER.

GRINDING MILL.

APPLICATION FILED NOV. i6. 1915.

5 SHEETS-SHEET 5.

JOHN W. COVER,

ofl Tacoma, WASHINGTON.

GnINnING-MILI..

Application led November 16, 1915. Serial No. 61,8417.

' To aZZ @from z' may concern.'

- mill.

Be 1t known that I, JOHN W. citizen of the United States, and resident of Tacoma, Pierce county, Washington, have invented certain new and useful Improve- COVER, a

ments in Grinding-Mills, of which the following is a specification. c

y invention relates to grinding mllls, and particularly to mills 4which are used extensively in grinding ores. These mills are however adapted for grinding materials of other kinds.

The object of my invention is to improve the construction of such mills `so, as to increase their eificienc make'them more easy of repair and keeping in order, increase their capacity and reduce the power required to run them.

Otherl objects will appear from a study of these specifications and the accompanying drawings.

The features of the device as herein shown and described, which I consider novel and upon which I desire patent protection, will be defined in the claims which terminate this specification.

In the accompanying drawings I have shown my invention in the form of .construction which I now prefer to use. It is not, however, to be understood that my invention is to be limited to the exact construction herein shown and described.

Figure 1 is a side elevation of a complete mill. Fig. 2 is an end elevation of the same Fig. 3 is a central longitudinal section on a vertical plane. Fig. 4 is a section through the mill taken on a vertical plane which is perpendicular to the axis of the mill. Fig. 5 is a vertical axial section of a modified construction. Fig. 6 is an end view, partly in section. Fig. 7 is a section taken alongside plate 87 of Fig. 5; and Fig. 8 is a view of the opposite end of the mill of Fig. 5.

This mill, in its general character, comprises a drum or cyllnder which is mounted to Yturn upon its axis and which has a series of circular seats carried by its heads, these being arranged in pairs,

laced rods or bars, the bars of each group going 4sufficient in number to fill a material part of the cross sectional area of their seats, and yet loose enough to permit rather central ax1s by the turning of the free rolling or tumbling to `take each grou as they are carried a lplace in out the drum or Speciiication of Letters Patent.

These holes in opposite in which seats are.

Patented Aug.. 15, 1916.

cylinder. While this general feature is not now broadly new, I provements in construction which contribute materially to the perfection of the machine and its operation.

The main part'l of the drum proper, consists of two heads l, and a metal sheet 2, which connects the heads. The heads are preferably composed of cast iron, while the connecting sheet is composed of rolled metal. The heads at each end are, or may be, alike in construction. Each has la centrally placed hollow sleeve or neck, 10, making a large opening through which the material bein operated upon may be inserted and discharged. Upon the outer end of this neck is formed an external trackway or wheel surface, 12, which bears wheels 5, of which two are placed under each end of the drum. These wheels are journaled in brackets 50, or any other sutable type of frame. They are also preferably provided with slight flanges to prevent displacement of the drum axially.

Each neck 10 has been shown as rovided with external lugs 13, located at a out the middle of its length, to which a s rocket or chain wheel may be bolted, there y providlng means whereby power may be applied to turn the drum. It is however, not necessary to apply the chain wheel to more than one end.

Each head has a ian'ge 14 projecting in an axial direction at its outer edge. sheet metal body 2 is secured to these flanges. Between the neck 10 and the outer edge of the head, it is provided with a' series of round holes in which bushings are placed for the freception of the grinding. bars. heads are placed in allnement, so that the rods, when in place, are parallel with each other and the axis of the drum.

The bushings consist of rings 3, of cast ironof suiicientlength axially, to provide a properl bearing surface for the ends of therods. These rings, or their inner surface, may be chilled or otherwise treated to give them a wear-resistant surface; or they may be made of special material. They are provided with a fiange 30 of suincient depth to engagethe outer face of the head to thereby x them in position. Theinner surface hese rings or bushings, may be made smooth, corrugations or irregularities, as shown at 35, to insure that there can upon carrying loe be no sliding of the bars over the surface of the rings, but that they shall be raised until `the upper surface of the pile getsirr p clined to such a degree that the uppermost will roll over the others, thereb producing ,a grinding and powdering lof t e materials which may be cau ht between them.

The openings o the rings or bushings are l closed byplates, 32. Plates 32 and bushings 3, have slots 33 extending inward from their outer edge, for the reception of securing bolts 34:, which are secured in the head.

By taking 0E one of these plates the bars of any group may be examined, removed and replaced at will.

above a group of the bars 4 at that side of the drum which` is moving upward when turning. At the edges of these screen openings which are lowermost under the same conditions, a narrow delecting plate 24 is secured, projecting inwardly from the shell enough that materia of the drum. The

dropped therefrom will fall upon the next followin groupof bars. In this way the feedin o the material vvithin the drum upon t e bars is secure lugs 18 upon its inner side, extending substantially from its outer edge tothe neck 10. These ribs maybe placed opposite the external ribs 11. One function of these ribs is to strengthen the head. Those at the inner side of the head have another urpose. They are placed midway between t e seats for the bars and have plates 25 secured thereto and extending from head to head. These plates serves as stiit'ening members of the drum and also as deiiecting plates to direct material dropping from each group of bars upon the xed central screen 6. This central screen is supported upon two bars 62 which extend through theA drum within the opening of the necks 10, these bars may "be supported externally of the drum in any suitable manner. It is preferably inclined toward each side so as to 'deposit all material which will not pass through its mesh, upon the groups of bars. Discharge chutes 61, laced beneath the screen 6, 'dischargethe nely ground material which passes the4 mesh of screen 6, without the drum. The

material which is discharged through the screens 22 in the outer shell of the drum, is collected by the pan 7 which extends beneath the drum.

' To prevent drip from running out the neck openings, the inner ends of the necks are madev to extend inward a slight distance projection of this is' nach head has radially disposed' ribs or' and are tapered inwardly, as is shown by the flange 15.

The central screen 6 is mounted to slide lengthwise upon the bars 62, so that it may be removed and replaced at will without affecting any other part of the mill.v In operating the mill the pan or tank 7 into which the lower side of the drum dips is -kept filled with Water to such a point that the lowermost of the roups of grinding bars are more or less su merged.

Another modication of construction is shown in Figs. 5 to 8. In this webs orv diaphragms 8' are provided between the heads, in which the bushings 3 are mounted. These are provided with lugs 80 for attachment to the outer shell and are cut away, as at 81, between these lugs, thus preventing their acting as cut-offs for the materials in the drum.

In Figs. 5 and 8 I have shown screens 85 of segmental shape at the ends of the drum. These screens are placed at the outer side of angularly projecting hoods 86, so that when one of these reaches the bottom of the drum the screen surface `races downwardly. With this type of construction the tank 7` would not ordinarily be used.

Where screens are used upon the ends of the drum, it is desirable to keep the ends of the grindingrods from engaging with the drum heads. I then employ a diaphragm or plate 87 which is secured a short distance inward from the head and against which the ends of the grinding rods 4 abut. Such a diaphragm may be placed. at each or at only one end of the drum, as desired. One lof the heads is preferably provided with hand holes, ordinarily covered by plates 88, giving access each to two of thegroups of grindlng'bars 4. p

What I claim and desire vto secure by Letters Patent is:

1. A grinding mill comprising av drum mounted to be rotated and containing a se'- ries of pockets annularly disposed 'within its outer shell, a series of grinding rods loosely placed within each pair of pockets,

`radially/placed deflecting plates between the sets of grinding rods, and a fixed screen lying in the central part of the drum in position to receive the discharge from said delecting plates.

2; A grinding .mill comprising a drum mounted to rotate, a series of -circular pockets secured in pairs to opposite heads, and spaced about the outer part thereof, grinding bars loosely rouped in said pockets, screens placed in t e eri hery of the drum between each group o grindin bars and to be beneath a ra ial plane etween said groups at the side of the drum which is moving upward, deflecting plates connecting opposite heads and radially placed be.-

ltween each group of grinding bars, said plates having their outer edges spaced inward from the outer shell of the drums.

3. A grinding mill comprising a drum\ mounted to rotate, a series of circular pockets adapted to serve as seats for the grinding bars and placed about the outer zone of the drum, grinding bars seated in said pockets, delecting plates radially placed between each group of grinding bars and having their outer edges spaced inward from the outer shell of the drum, the'outer shell of the drum having screened openings Abetween each group of grinding bars and at one side of the plane of the corresponding deflecting plate, and a plate extending inward from the shell at the other side of said screen openings from that of said delecting plate.

4. A grinding millv comprising a .drum having a series of groups of grinding bars constrained to occupy as a whole a definite dially. positioned deflecting plates between the groups of grinding bars having their outer edges inward from the outer shell and substantially alined with the other edge of the screens in the outer shell, a screen occu- 4 pying the space within the groups of grinding bars and a discharge chute beneath said centrally placed screen and extending without the drumthrough axial openings thereof.

Signed at Seattle, Washington, this 28th day of October, 1915.

JNO. W. oovnn. 

